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And now, finally, after centuries, a scientific mystery has been solved.

We are beginning to understand how miracle fruit can make something very sour, instead, taste very sweet. Miracle fruit: what is it? Have you heard of it?

My first introduction to miracle fruit (also called miracle berry) was when I was in a radio station, and the next guest after me was a chef.

In the studio, live on-air, he gave me a small red berry to pop into my mouth. I bit into it, spat out the small black seed and, as I chewed it, the mashed-up pulp of miracle fruit mixed with my saliva and spread all across the inside of my mouth and, especially, onto my tongue.

It tasted fairly neutral. It certainly did not seem particularly sweet. Perhaps it had a hint of sweetness.

I swallowed the pulp, and after a minute, the chef gave me a lemon to chew. It tasted like candied lemon! Vinegar tasted like apple juice!

Anything acid tasted sweet. And not just sweet, but very, very sweet.

On the other hand, banana still tasted just like banana.

Miracle fruit comes from a shrub, Synsepalum dulcificum, that is native to tropical West Africa. This shrub grows up to six-meters tall, and has brown flowers with small red fruit or berries. Yup, they're the miracle fruit or miracle berry.

The locals have long used it to add sweetness to palm wine or beer that's gone sour, or to make stale acidified maize bread more palatable. The effect lasts for a few hours.

Miracle fruit first came to the attention of Europeans in 1725, when the explorer, Chevalier des Marchais, came across it on a botanical expedition in tropical West Africa.

In 1852, a chemist, W.F. Daniell, was the first European to scientifically study it, and he gave it the name 'miraculous berry'.

It took until 1968 for two separate groups of scientists to isolate the active ingredient. It turned out to be a chemical that was mostly protein with about 191 amino acids, and about 14 per cent carbohydrate (sugars such as mannose, galactose and fucose). The active ingredient was given the name 'miraculin'.

Soon after miraculin was isolated, Robert Harvey, an American biomedical postgraduate student, became aware of its wonderful property.

At the time, the artificial sweeteners (which have sweetness, and virtually zero kilojoules) had a slightly noticeable after-taste.

But Robert Harvey realised that miraculin did not. He tried mightily to market it as an alternative sweetener, one that was based entirely upon a natural product.

But in 1974, just as he was about to launch it, the US Food and Drugs Administration refused to classify it as 'generally recognised as safe', despite the West Africans having eaten miraculin for centuries with no problems.

Robert Harvey could not afford the several years of testing needed, so miraculin never made it into the marketplace.

However, people have been using miracle fruit to run what they call 'flavour tripping parties'. You pay your money ($10–15 or so), turn up, eat your single red miracle fruit and then, after a minute-or-so, start browsing on the unusual range of foods that have been laid out.

Mind you, the effect happens only in the presence of something rather acid.

So Guinness, when you add some acid lemon sorbet, suddenly tastes like a chocolate milkshake. Tabasco sauce now tastes like hot doughnut glaze. Lemons taste like candied lemons. Goat cheese now tastes like cheesecake.

On a philosophical level, does miracle fruit (or berry) change reality, and even deeper, do we all experience reality differently depending on the context?

Don't know; that's much too hard for science to answer.

But a much easier question to answer is: how do you taste something?

Mostly, you use your tongue, which is linked to your brain. Of course, the sense of smell is also involved, but I won't talk about that right now.

Your tongue has a bumpy surface because it's covered with 2000–8000 raised taste buds of different sizes and shapes.

Some of them look like tiny mushrooms, others like mini-volcanoes and some like cylindrical shrubs. These taste buds contain the receptors for the five basic tastes of sweet, sour, bitter, salt and umami.

Unfortunately, there is simply too much left to chew on, and so I'll finish off the answer of how miracle fruit works, next time.